pressure

[waco58]

Does anyone know what would be the max pressure for the 7x57 in a Ruger Model 77 M II

[BlkHawk73]

  The SAAMI Maximum average pressure for the 7x57 is 46,000 CUP.  I'd stick to that max. 

[Slamfire]

That SAAMI maximum average pressure is low enough so factory rounds won't eventually damage the old Spanish rifles based on the Model 93 Mauser. There ain't any good reason you can't load your Ruger up to a more normal maximum of 55 or 60 kpsi. Some of the rounds chambered in that rifle have SAMMI maximum average pressures of 65 kpsi. I'd advise you to stay on the lower side, as there's no way you can determine the pressure of your loads.

[Lone Star]

There is absolutely no reason to stick with 19th centruy pressure levels in your modern Ruger M77.   Hornady realizes this and publishes loads well above that level.  Speer publishes loads around 50,000 cup.  Alliant uses data up to 49,000 psi.   Don't be afraid to up the pressure - but use tested load data.


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